#define _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>
int main()
{
	int sum = 0;
	int time = 2;
	scanf("%d", &sum);
	int i = 0;
	while (sum >= 12)
	{
		sum -= 12;
		time += 4;
	}
	printf("%d", time);
	return 0;
}